c. Use the regression equation to find the forecast for period 9. To find the equation you can use Excel or any other software of your preference. A tutorial is available for you if you wish to use it.

4. A forecasting method resulted in the following forecasts shown by the data in the following table.

PeriodDemandForecast1

2

3

4

5

6

7

8

9

10

132

141

137

159

146

162

166

175

194

181

127

130

133

135

139

144

149

155

161

169

a. Use the data to calculate the MAD.

b. Find a regression equation for the demand data.

c. Use the regression equation to forecast demand for period 11.

d. Is the regression method preferred over the method used? Why or why not?